It's been known for years that most browsers ended flash.
If you're having this level of trouble, you'd want to make a CS ticket to bind your account. Common issues with login happen when the email / username have non alphanumeric (0-9, A-Z) characters or you've tried to change the password multiple times quickly and triggered some sort of security measure.
Faster responses are probably gotten on the official discord than forum posts:
https://discord.gg/narutoenLog in in order to Post. LOGIN | Register